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3 years ago

List 3 examples of pure substances

Chemistry

2 answers:

ollegr [7]3 years ago

4 0

1. water (H2O) 2. helium (He) 3. iron (Fe)

Brrunno [24]3 years ago

4 0

Table salt, table sugar, and gold.

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2.00 L of a gas is collected at 25.0°C and 745.0 mmHg. What is the volume at 760.0 mmHg

Leviafan [203]

1.7960L

Explanation:

the mass of the gas is constant in both instances

pv/T=constant(according to pv=nRT)

745mmHg*2L/298K=760mmHg*v/273K

v=1.7960L

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3 years ago

The radius of the smaller circle is 8 feet. The distance from the rim of the inner circle to the rim of the outer circle is 3 fe

postnew [5]

Answer:

178.98 sq. feet

Explanation:

The path and the garden has been shown in the figure below. The green area is the garden and the area in brown is the path.

It has been given that,

Radius of garden = 8 feet

So, the area of garden = 3.14 × 8 × 8 = 200.96 sq. feet

The total radius of the land including garden and path = 8 + 3 = 11 feet

So, the total are of land including garden and path = 3.14 × 11 × 11 = 379.94 sq. feet

So, the area of path = Total area of the land - area of garden

Area of path = 379.94 - 200.96 = 178.98 sq. feet

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4 years ago

How are the environments of a desert and a tundra different?

Alexeev081 [22]

Answer:

A tundra is less humid than a desert

Explanation:

6 0

2 years ago

Read 2 more answers

How much more would a 20.0 gallon tank for propane

Jet001 [13]

Answer: 20 + 1 + 3.8 + 2.4 +27 = 54.2

Explanation: 20 gallons plus 1 gallon plus 3.8 plus 2.4 plus 27 equals to a total number of 54.2 gallons for the propane.

3 0

3 years ago

How many liters of hydrogen gas will be produced at STP from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phos

Alexeev081 [22]

Answer: The volume of hydrogen gas produced will be, 12.4 L

Explanation : Given,

Mass of $H_3PO_4$ = 54.219 g

Number of atoms of $Mg$ = $7.179\times 10^{23}$

Molar mass of $H_3PO_4$ = 98 g/mol

First we have to calculate the moles of $H_3PO_4$ and $Mg$ .

$\text{Moles of }H_3PO_4=\frac{\text{Given mass }H_3PO_4}{\text{Molar mass }H_3PO_4}$

$\text{Moles of }H_3PO_4=\frac{54.219g}{98g/mol}=0.553mol$

and,

$\text{Moles of }Mg=\frac{7.179\times 10^{23}}{6.022\times 10^{23}}=1.19mol$

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

$3Mg+2H_3PO_4\rightarrow Mg(PO_4)_2+3H_2$

From the balanced reaction we conclude that

As, 3 mole of $Mg$ react with 2 mole of $H_3PO_4$

So, 0.553 moles of $Mg$ react with $\frac{2}{3}\times 0.553=0.369$ moles of $H_3PO_4$

From this we conclude that, $H_3PO_4$ is an excess reagent because the given moles are greater than the required moles and $Mg$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $H_2$

From the reaction, we conclude that

As, 3 mole of $Mg$ react to give 3 mole of $H_2$

So, 0.553 mole of $Mg$ react to give 0.553 mole of $H_2$

Now we have to calculate the volume of $H_2$ gas at STP.

As we know that, 1 mole of substance occupies 22.4 L volume of gas.

As, 1 mole of hydrogen gas occupies 22.4 L volume of hydrogen gas

So, 0.553 mole of hydrogen gas occupies $0.553\times 22.4=12.4L$ volume of hydrogen gas

Therefore, the volume of hydrogen gas produced will be, 12.4 L

4 0

3 years ago